Former JPMorgan head of government relations Tom Block put
together this graphic – which Tom Lee included in his latest note
to clients – showing the bank's estimated probabilities on four
different fiscal cliff outcomes, conditional on who wins the
presidential election in November:

JPMorgan

And here is JPMorgan chief U.S. economist Michael Feroli's
estimates on how GDP growth would be impacted under each of the
four outcomes outlined above:

JPMorgan

So, even in their base case, JPMorgan is looking for a 0.5
percent reduction in GDP growth in the first quarter of 2013
followed by a 0.3 percent reduction in the second quarter from
the effects of the fiscal cliff.